A method for synthesizing trifloxysulfuron

Abstract

The present application relates to the preparation technology field of sulfonylurea herbicide, propose a trifloxysulfuron synthesis method, including the following steps: S1, 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide is dissolved in solvent, obtain mixed solution, the solvent is acetonitrile and acrylonitrile;S2, 4, 6-dimethoxy pyrimidine-2-yl carbamic acid phenyl ester and catalyst are added to the mixed solution, and reaction is carried out to obtain trifloxysulfuron. Through the above technical scheme, the problem of low purity and low yield of trifloxysulfuron synthesis in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of synthesis of sulfonylurea herbicides, in particular to a trifloxysulfuron synthesis method. BACKGROUND

[0002] Trifloxysulfuron is a new type of sulfonylurea herbicide, mainly used for the prevention and control of broadleaf and sedge weeds. Similar to other sulfonylurea herbicides, trifloxysulfuron can inhibit the activity of plant acetyl lactate synthase to hinder the synthesis of amino acids, thereby inhibiting the growth of plants and eventually leading to their death. Trifloxysulfuron is usually synthesized from intermediates 3- (2, 2, 2-trifluoroethoxy) pyridine-2-sulfonamide and 4, 6-dimethyl pyrimidine-2-yl carbamic acid phenyl ester. However, the conventional synthesis method has low product purity and low yield, which is not conducive to industrial production. SUMMARY

[0003] Based on the above problems, the present application provides a trifloxysulfuron synthesis method, which solves the problems of low purity and low yield of trifloxysulfuron synthesis in the prior art.

[0004] The technical scheme of the present application is as follows:

[0005] A trifloxysulfuron synthesis method, comprising the following steps:

[0006] S1, dissolving 3- (2, 2, 2-trifluoroethoxy) pyridine-2-sulfonamide in a solvent to obtain a mixed solution, wherein the solvent is acetonitrile and propylene nitrile;

[0007] S2, adding 4, 6-dimethoxy pyrimidine-2-yl carbamic acid phenyl ester and a catalyst to the mixed solution, and reacting to obtain trifloxysulfuron.

[0008] As a further technical scheme, the volume of acetonitrile > the volume of propylene nitrile.

[0009] In the present application, the volume of acetonitrile is limited to be greater than the volume of propylene nitrile, which further improves the purity and yield of trifloxysulfuron.

[0010] As a further technical scheme, the volume of acetonitrile > 1.5 times the volume of propylene nitrile.

[0011] In the present application, the volume of acetonitrile is limited to be greater than 1.5 times the volume of propylene nitrile, which further improves the purity and yield of trifloxysulfuron.

[0012] As a further technical scheme, the volume ratio of acetonitrile to propylene nitrile is 11:4-12:3.

[0013] The volume ratio of acetonitrile and acrylonitrile is 11:4-12:3 in the application, which further improves the purity and yield of trifloxysulfuron.

[0014] As a further technical solution, the mass-volume ratio of the 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide and the solvent is 1g:11.5-23.5mL; the molar ratio of the 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide and the 4,6-dimethoxy pyrimidine-2-yl carbamic acid phenyl ester is 1:1-1.5.

[0015] As a further technical solution, the catalyst is DBU, and the mass-volume ratio of the 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide and the catalyst is 1-2g:1mL.

[0016] DBU is 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0017] As a further technical solution, the temperature of the reaction is 15-35℃, and the reaction time is 1-3h.

[0018] As a further technical solution, after the reaction is completed, the post-treatment is also included, and the post-treatment is: the solution after the reaction is concentrated, filtered, washed, and dried to obtain trifloxysulfuron.

[0019] As a further technical solution, before the filtration, a mixed solution of hydrochloric acid and water is added to the obtained residue after the concentration for crushing.

[0020] As a further technical solution, in the mixed solution of hydrochloric acid and water, the volume ratio of hydrochloric acid to water is 1:3-5.

[0021] The working principle and beneficial effects of the application are:

[0022] The application provides a trifloxysulfuron synthesis method, acetonitrile and acrylonitrile are compounded as a reaction solvent, the raw material is dissolved in the mixed solvent, and the reaction is carried out under the action of a catalyst. The application of the mixed solvent improves the solubility of the raw material in the solvent, and significantly improves the purity and yield of trifloxysulfuron. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor also relate to the protection scope of the application.

[0024] In the following examples and comparative examples:

[0025] The concentration of hydrochloric acid is 2 mol / L.

[0026] Example 1

[0027] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (the volume ratio of acetonitrile to acrylonitrile in the mixed solvent is 6:9), then add 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU, and react at 25°C for 2 h. Concentrate the obtained solution by rotary evaporation, add a mixed solution of hydrochloric acid and water (the volume ratio of hydrochloric acid to water in the mixed solution is 1:4) to the residue, and pulverize the residue to obtain a white solid. Filter the white solid, wash it with water and diethyl ether in sequence, and dry it under vacuum to obtain triflusulfuron.

[0028] Example 2

[0029] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 3000 mL of a mixed solvent of acetonitrile and acrylonitrile (the volume ratio of acetonitrile to acrylonitrile in the mixed solvent is 6:9), then add 275.3 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 256 mL of DBU, and react at 15°C for 1 h. Concentrate the obtained solution by rotary evaporation, add a mixed solution of hydrochloric acid and water (the volume ratio of hydrochloric acid to water in the mixed solution is 1:3) to the residue, and pulverize the residue to obtain a white solid. Filter the white solid, wash it with water and ethanol in sequence, and dry it under vacuum to obtain triflusulfuron.

[0030] Example 3

[0031] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 6000 mL of a mixed solvent of acetonitrile and acrylonitrile (the volume ratio of acetonitrile to acrylonitrile in the mixed solvent is 6:9), then add 412.89 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 130 mL of DBU, and react at 35°C for 3 h. Concentrate the obtained solution by rotary evaporation, add a mixed solution of hydrochloric acid and water (the volume ratio of hydrochloric acid to water in the mixed solution is 1:5) to the residue, and pulverize the residue to obtain a white solid. Filter the white solid, wash it with water and ethanol, and dry it under vacuum to obtain triflusulfuron.

[0032] Example 4

[0033] To 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide was added 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (volume ratio of acetonitrile to acrylonitrile in the mixed solvent was 1:1), followed by the addition of 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU, and the mixture was stirred at 25°C for 2 hours. The resulting solution was concentrated by rotary evaporation, and a mixed solution of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixed solution was 1:4) was added to the residue to pulverize the residue to obtain a white solid. The solid was filtered, washed with water and diethyl ether in this order, and dried under vacuum to obtain triflusulfuron.

[0034] Example 5

[0035] To 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide was added 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (volume ratio of acetonitrile to acrylonitrile in the mixed solvent was 8:7), followed by the addition of 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU, and the mixture was stirred at 25°C for 2 hours. The resulting solution was concentrated by rotary evaporation, and a mixed solution of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixed solution was 1:4) was added to the residue to pulverize the residue to obtain a white solid. The solid was filtered, washed with water and diethyl ether in this order, and dried under vacuum to obtain triflusulfuron.

[0036] Example 6

[0037] To 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide was added 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (volume ratio of acetonitrile to acrylonitrile in the mixed solvent was 9:6), followed by the addition of 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU, and the mixture was stirred at 25°C for 2 hours. The resulting solution was concentrated by rotary evaporation, and a mixed solution of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixed solution was 1:4) was added to the residue to pulverize the residue to obtain a white solid. The solid was filtered, washed with water and diethyl ether in this order, and dried under vacuum to obtain triflusulfuron.

[0038] Example 7

[0039] To 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide was added 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (volume ratio of acetonitrile to acrylonitrile in the mixed solvent was 10:5), followed by the addition of 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU, and the mixture was stirred at 25°C for 2 hours. The resulting solution was concentrated by rotary evaporation, and a mixed solution of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixed solution was 1:4) was added to the residue to pulverize the residue to obtain a white solid. The solid was filtered, washed with water and diethyl ether in this order, and dried under vacuum to obtain triflusulfuron.

[0040] Example 8

[0041] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (volume ratio of acetonitrile to acrylonitrile in the mixed solvent is 11:4), and then add 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU. React at 25°C for 2 h, concentrate the resulting solution by rotary evaporation, and pulverize the residue with a mixture of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixture is 1:4) to obtain a white solid. Filter, wash the solid with water and diethyl ether in this order, and dry under vacuum to obtain triflusulfuron.

[0042] Example 9

[0043] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (volume ratio of acetonitrile to acrylonitrile in the mixed solvent is 12:3), and then add 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU. React at 25°C for 2 h, concentrate the resulting solution by rotary evaporation, and pulverize the residue with a mixture of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixture is 1:4) to obtain a white solid. Filter, wash the solid with water and diethyl ether in this order, and dry under vacuum to obtain triflusulfuron.

[0044] Example 10

[0045] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 4500 mL of a mixed solvent of acetonitrile and acrylonitrile (volume ratio of acetonitrile to acrylonitrile in the mixed solvent is 13:2), and then add 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU. React at 25°C for 2 h, concentrate the resulting solution by rotary evaporation, and pulverize the residue with a mixture of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixture is 1:4) to obtain a white solid. Filter, wash the solid with water and diethyl ether in this order, and dry under vacuum to obtain triflusulfuron.

[0046] Comparative Example 1

[0047] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 4500 mL of acetonitrile, then add 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU, react at 25°C for 2 h, concentrate the obtained solution by rotary evaporation, add a mixed solution of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixed solution is 1:4) to the residue, and pulverize to obtain white solid, filter, wash with water and diethyl ether in sequence, and dry under vacuum to obtain triflusulfuron.

[0048] Comparative Example 2

[0049] Dissolve 256.2 g of 3-(2,2,2-trifluoroethoxy)pyridine-2-sulfonamide in 4500 mL of acetonitrile, then add 357.9 g of phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and 170 mL of DBU, react at 25°C for 2 h, concentrate the obtained solution by rotary evaporation, add a mixed solution of hydrochloric acid and water (volume ratio of hydrochloric acid to water in the mixed solution is 1:4) to the residue, and pulverize to obtain white solid, filter, wash with water and diethyl ether in sequence, and dry under vacuum to obtain triflusulfuron.

[0050] Experimental results:

[0051] The triflusulfuron prepared in Examples 1-10 and Comparative Examples 1-2 is analyzed for purity by high performance liquid chromatography, and the yield is calculated according to the following formula, and the results are recorded in Table 1.

[0052] Yield = actual yield x purity ÷ theoretical yield x 100%.

[0053] Table 1: Yield and purity of triflusulfuron

[0054]

[0055] Compared with Comparative Examples 1-2, the solvent in Example 1 is acetonitrile and propylene cyanide, and the yield and purity of triflusulfuron prepared in Example 1 are higher than those of Comparative Examples 1-2, indicating that the combination of acetonitrile and propylene cyanide as the reaction solvent improves the yield and purity of triflusulfuron.

[0056] Compared with Examples 1 and 4, the volume of acetonitrile in Examples 5-10 is greater than that of propylene cyanide, and the yield and purity of triflusulfuron prepared in Examples 5-10 are higher than those of Examples 1 and 4, indicating that when the volume of acetonitrile is greater than that of propylene cyanide, the yield and purity of triflusulfuron are improved.

[0057] Compared with Examples 5-6, the volume of acetonitrile in Examples 7-10 is >1.5 times the volume of acrylonitrile, and the yield and purity of trifloxysulfuron prepared in Examples 7-10 are higher than those of Examples 5-6, indicating that when the volume of acetonitrile is >1.5 times the volume of acrylonitrile, the yield and purity of trifloxysulfuron are improved.

[0058] The yield and purity of trifloxysulfuron prepared in Examples 8-9 are higher than those of the remaining examples, indicating that when the volume ratio of acetonitrile to acrylonitrile is 11:4-12:3, the yield and purity of trifloxysulfuron are improved.

[0059] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for synthesizing flupyrsulfuron comprising, The method comprises the following steps: S1, dissolving 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide in a solvent to obtain a mixed solution, wherein the solvent is acetonitrile and acrylonitrile; S2, adding phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate and a catalyst to the mixed solution to react to obtain trifloxysulfuron; The volume of acetonitrile is greater than the volume of acrylonitrile.

2. The method for synthesizing trifloxysulfuron according to claim 1, wherein: The volume of acetonitrile is greater than 1.5 times the volume of acrylonitrile.

3. A method for synthesizing trifloxysulfuron according to claim 2, characterized in that: The volume ratio of acetonitrile to acrylonitrile is 11:4-12:

3.

4. The method for synthesizing trifloxysulfuron according to claim 1, wherein: The mass-volume ratio of 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide to the solvent is 1g:11.5-23.5mL; the molar ratio of 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide to phenyl 4,6-dimethoxypyrimidin-2-ylcarbamate is 1:1-1.

5.

5. The method for synthesizing trifloxysulfuron according to claim 1, wherein: The catalyst is DBU, and the mass-volume ratio of 3-(2,2,2-trifluoroethoxy) pyridine-2-sulfonamide to the catalyst is 1-2g:1mL.

6. The method for synthesizing trifloxysulfuron according to claim 1, wherein: The reaction temperature is 15-35℃, and the reaction time is 1-3h.

7. The method for synthesizing trifloxysulfuron according to claim 1, wherein: After the reaction is completed, a post-treatment is further included, wherein the post-treatment is: concentrating the solution after the reaction, filtering, washing, and drying to obtain trifloxysulfuron.

8. The method for synthesizing trifloxysulfuron according to claim 7, wherein: Before the filtering, a mixed solution of hydrochloric acid and water is added to the residue obtained by the concentrating to crush.

9. The method for synthesizing trifloxysulfuron according to claim 8, wherein: In the mixed solution of hydrochloric acid and water, the volume ratio of hydrochloric acid to water is 1:3-5.

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